System of radiotelegraphy



March 22 192 H. CHIREIX SYSTEM OF RADIOTELEGRAPHY Filed July 20. 1923 n w illll a r I ALTERNATOR flower-tot $51; his, (1%

HENRI CHIREIX Ja /MW Oil Patented Mar. 22, 1927.

UNITED STATES HENRI dHIRnIX, on'rnnrs, FRANCE.

SYSTEM OF RADIOTELEGRAPI-IY.

Application filedJuly 20, 1923, Serial No. 652,804, and in France September 13, 1922.

The object of the present invention is to accelerate the establishment of a current in the antenna during the keying, and more generally, to deliver into the antenna. a larger mean-power for dots than for dashes.

When the Morse code is used the duration of the dots is only that of the clashes. In response to the sending of a dot,thc receiving station receives at best A; the energy of a dash, the permanent sending current remaining the same in both cases (by the expression permanent sending current is meant the value of the effective intensity under established conditions). Due to time constants at sending and at receiving, the energy received with a. dot is much weaker when the transmitting speed is increased, and a point will'be reached when it will be insufficient for actuating the writing appa ratus.

In accordance with the present invention, the sending circuits are provided with such characteristics that, upon the sending of dots or at the beginning of the signals the permanent current will be larger than during the sending of dashes, or than at the end of the long signals.

Varying means maybe employed for practicing the present invention; the following description exemplifies some of the circuits that may be employed and should be read in connection with the accompanying drawing in which- Fig. 1 shows a circuit arrangement conforming to the invention,

Fig. 2 shows a modification thereof,

Fi 3 shows a modified contact device which may be substituted for that shown at 4 in Fig. l, i

Fig. 4. shows a modified circuit arrangement in which the antenna current is used to operate the several contact devices, and

Figs. 5 and 6 show further modifications of the system illustrated in Fig. 4.

In accordance with the arrangement shown in Fig. 1, 1 is the alternator which feeds the antenna. through leakage transformer 2. The primary circuit comprises a capacity 3 the terminals of which are connected with a contact making device 4, a second contact device 5 being shunted around a portion of the antenna self-induction coil. Assuming that the contact makers 4 and 5 are open, the two circuits are tuned to give maximum current in the antenna. Upon the closing of the two contact makers, by

suitably determining the portion of the inductance short-circuited by 5, we may provide that the tuning is unchanged. It will be readily seen that in the latter case, for the same E. M. F. of the alternator, the permanent current in the antenna will be lower since the coupling between the circuits is reduced. In accordance with this arrangement the contact devices 4 and 5 are normally closed, and are opened upon the sending of a dot. In this manner dots will be obtained which correspond to a larger power in the antenna than the dashes.

It should be noted that, in accordance with one modification, instead of providing ia capacity at 3, a self induction may be provided if the open periods of relay l are changed into closed periods. In the same manner, in accordance with a second modification, instead of using 5 for controlling an inductance, it may be used for controlling a capacity. Instead of modifying the resonance conditions by means of a contact device, any other arrangements may be provided without departing from the spirit of the present invention. For example, we may employ inductances variable bythe saturation of a magnetic core; these inductances being, of course, arranged in such a manner that the circuit traversed by the alternating current does not react on the direct current circuit. The saturated inductance shown in Figs. 2, 5 and 6 must be considered as arranged to serve in this manner. Fig. 2 illustrates a circuit of this character. In this figure; 3 is a magnetic core inductance having a saturatii'ig winding l; 5 is another magnetic core inductaiice having a saturating winding (5. Upon the sending of dots the winding l is supplied with current and the winding 6 is disconnected by any suitable means. It should be noted that the Variable inductances may be provided in series, like 3, or in parallel, like 5, with an inductance in series, but in each case the cutting in and out of the saturating windings must be suitably provided for.

Instead of increasing the energy only in the dots, it may be increased at the beginning of all the signals, whereby the establishment of the conditions is accelerated. All we need for this purpose is that, depending on the circuit arrangements used, the above described operations be performed at the beginning of each and every signal instead of only upon the sending of dots. This may be accomplished by an induction eliect the duration of Which is determined by thetime constants of the different circuits. Furthermore, acontact device may be used Which is provided With front and baclccontacts 4; and a interconnected in the manner shown in Fig. 3. This. contact device is operated by suitable means upon the sending of each signal, and its circuit will be open; only during the movement of its movable contact; Such contact device. should be substituted for eachcontact device 4 and 5 01* Fig. 1.

The antenna current may also be used for this purpose.

Thismodification of the invention is illus trated in Fig. 4: in which contact devices-are used.

6 is some kind of rectifier (tube, etc.) coupled at 7 With the antenna. is built upin the antenna, the EtM. F. in-

duced in the circuit ot the rectifier generates;

a rectified current Which traverses the magents of contact devices 4 and 5. Aftercertain length of time the magnets-Will close their contacts, and the permanent state will be changed in the above described manner. It should be noted that such control of the variations by the antenna current automaticallyinsuresthe stability of the state. The closer the coupling 7 the quicker Will the new state be established, thelooser. the coupling, the slower will be the establishment of the new conditions. The contact devices- 4 and 5 may of course beprovided with re:- turn springs or adjustable opposing wind: ings so as to vary the closing: time-oft the relay. It is advisable to connect condensers 8 and 9 With the terminals of the contact de? vice windings.

Fig. 5 shows another embodiment of the same modification of the invention. In this case use ismade of an. inductance having auxiliary. saturation.

In this figure, the same reference numerals indicate thesamee'lements as in the preceding Fig. 2. Furthermore, the saturating windings.4t and 6 are supplied with current obtained from the antenna circuit, e. g. through a transformer 7, and. rectified by means of a tube 8- (or any equivalent there'- ot'). Condensers 10, 11 are provided in shunt with the saturating Winding so as to give a moreuniform value to the rectified current- The operation is as follows: At the beginning of the signals .the saturating self-induction 3 is saturated; by the battery 9'Which is connected: with Winding 4 through a suitable resistance 10. The self-induction 5-is not saturated. When the current builds up in the antenna, the self induction 8 is desaturated and: the self induction. 5 becomes saturated.

Fig. 6 shows another modification in which thesaturated selfinduction 3 isin parallel With the machine and the saturated self induction. 6 is in parallel with the antenna circuit.

iting the scope of the invention. The various circuits herein disclosed may be combined othercircnitsi provided for performing the same functions Without departing from the spirit'ot the present invention.

Having described. mi invention, What I claim is:

1'. The method of transmitting Morse signals which: consists in radiating a larger mean power for dotsthan fordashes.

Themethod of transmitting signals, consisting ofimpulses of unequal timeduration which consists in radiating substantially the same amount of energy for each impulse independent of. the time of such impulse.

3. The method: of transmitting signals consistingof impulses of unequal: time dura tion Which consists in radiating energy at a greater rate during impulses of shorter duration 4. The method of transmitting signals consisting of impulses of unequal time duration which consists in decreasing the energy radiated in each impulse after a predetermin-ed time period.

5. The method of transmitting radio signals consisting'of impulses of unequal time duration which consists in causing the antenna currentto have a value substantially in inverse ratio to the comparative length otsuch impulses.

6; The method of transmitting radio signals which consists in feeding to the antenna an. abnormally large current at substantially the beginning. only of signal impulses.

7. In radio. signalling apparatus, the combination of an antenna, signalling means, a source of power for said. antenna, means coupling said: source tow said antenna, tuning means for. adjusting the antenna current, and means controlled by saidsignalling means for varying the amount of said coupling Without varyingt-he established tuning of the antenna.

8.111: radio signalling apparatus, the combination of an antenna, a source of power for said antenna, signalling means, means coupling said source to said antenna, tuningmeansfor adjusting theantenna current, means operable by said signalling means to varythe amount of such coupling, and means simultaneously operable thereby to maintain the established tuning constant independent of the change in coupling.

9. In radioapparatus the combination of a tuned transmitting system including a transmission conductor, a source of energy and means for coupling said source to said duration conductor, signaling means, means operable by said signaling means for varying the cou pling between said source and said conductor and means to automatically maintain the established tuning in spite of changes in coupling, 1

10. In a radio signaling system a source of energy, a transmission conductor and a tuned circuit including coupling means for connecting said source to said conductor, signaling means and means operable by said signaling means for simultaneously varying the coupling and tuning to change the power output to said conductor and maintain the established tuning.

11. In a radio signaling system the combination of a transmission conductor, a source of energy connected to said conductor, means for automatically changing the power output to said conductor after a predetermined time interval and means for automatically tuning for maximum current in said conductor regardless of the power s output.

12. In radio apparatus the combination of a transmission system including a transmission conductor, an energizing circuit therefor and coupling means for connecting said conductor to said circuit, inductances in said conductor and said circuit including cores of magnetic material, tuning means for adjusting the current in said conductor and means for simultaneously varying the saturation of said cores to change the coupling and to maintain the established tuning.

13. In radio apparatus the combination of a transmission system including a transmission conductor, an energizing circuit therefor and coupling means for connecting said conductor to said circuit, inductances in said conductor and said circuit including cores of magnetic material, tuning means for adjusting the current in said conductor and means for simultaneously varying the saturation of said cores to change the coupling and maintain the established tuning, said last named means including a rectifier associated with said transmission conductor to vary the saturation of said cores in response to changes in the conductor current.

14. In a radio transmission system a transmission conductor, an energizing circuit therefor and means for coupling said circuit to said conductor, an inductance in said circuit and an inductance in said conductor each comprising an inductance winding, a core of magnetic material and a saturating winding for said core, tuning means including said inductances for adjusting the current in said conductor, a rectifier connected to said conductor and said saturating Win-dings to vary the coupling" between the conductor and energizing circuit and to maintain the established tuning on changes in the conductor current.

HENRI CHIREIX. 

